The present invention relates to a security system and particularly relates to a system which detects a distress signal transmitted in the locale of a monitoring station and communicates with a central response unit thereby to provide an indiction of the location of the security matter.
In one prior art system described in U.S. Pat. No. 4,189,721 to Doell, a portable transmitter activated a receiver disposed in a stationary monitor unit. The monitoring unit was coupled to an alternating current (ac) power source. The power from the ac power source was stepped down in a transformer and the output of the transformer was switched by a relay activated by the receiver. Upon closing the output circuit of the transformer, a second relay was activated which coupled the ac power to a third relay which in turn activated an audio alarm from the monitoring station. This prior art security system was reset after activation by a manual switch interposed between the ac power source and the audio alarm.